Lifetime ISA Calculator
See exactly how much the Lifetime ISA's 25% government bonus adds to your savings — and the real cost of withdrawing early, in cash, not just a scary percentage.
Estimate only. This is an illustrative projection, not a guarantee. Cash LISA rates change, and Stocks & Shares LISA values can fall as well as rise. Lifetime ISA rules, the contribution cap, the property price cap and age eligibility can change — always check the current rules on gov.uk. Not financial advice.
After 10 years
Where your pot comes from
| You pay in | £40,000 |
| Government bonus (25%) | £10,000 |
| Growth earned | £12,432 |
| Projected total | £62,432 |
The real cost of withdrawing early
Take money out for anything other than a first home or retirement, and the 25% penalty applies to the WHOLE amount — bonus included. Here's what that looks like on a simple £1,000 contribution:
You lose £63 of your OWN £1,000
That's really a 6.25% loss on your own money — not 25%.
The penalty isn't 25% off the bonus — it's 25% off everything, contribution and bonus together. That's why you end up with less than you paid in.
Cash or Stocks & Shares?
- Saving for a home in the next 1-5 years? A cash LISA protects your deposit from market ups and downs right when you need the money.
- Saving for retirement, or a home more than 5 years away? A Stocks & Shares LISA has historically grown faster over the long run, though your capital is at risk.
- Buying above £450,000? You can still keep the LISA for retirement, but you won't get the bonus toward that purchase — check the rules before you rely on it.
- Paying in more than £4,000/year doesn't get you extra bonus — put anything above that into a regular ISA or savings account instead.
How this is worked out
Each year's contribution (up to the £4,000 cap) earns a 25% government bonus, paid on top — so £4,000 in becomes £5,000 in your Lifetime ISA. We treat each year's contribution and bonus as a single deposit at the start of that year, then grow it at your chosen rate, compounding annually, for the remaining years.
The withdrawal penalty example shows the maths on a representative £1,000: with the 25% bonus it becomes £1,250, but an unauthorised withdrawal loses 25% of that — £312.50 — leaving £937.50. You only put in £1,000, so you've really lost £62.50 of your own money: 6.25%, not 25%. A Lifetime ISA is for a first home worth £450,000 or less, or retirement from age 60 — you can open one between 18 and 39, and keep paying in until you're 50.